An Automobile Dealer Wants to See If There Is a Relationship

An automobile dealer wants to see if there is a relationship between monthly sales and the interest rate.A random sample of 4 months was taken.The results of the sample are presented below.The estimated least squares regression equation is



= 75.061 - 6.254X

a.Obtain a measure of how well the estimated regression line fits the data.
b.You want to test to see if there is a significant relationship between the interest rate and monthly sales at the 1% level of significance.State the null and alternative hypotheses.
c.At 99% confidence,test the hypotheses.
d.Construct a 99% confidence interval for the average monthly sales for all months with a 10% interest rate.
e.Construct a 99% confidence interval for the monthly sales of one month with a 10% interest rate.